Picture frames have generally relied upon a flat picture mat for providing an overlay border around the periphery of the picture mounted in the frame. In lieu of mats, three dimensional framing materials have been suggested as seen in the Smith et al patent, U.S. Pat. No. 3,371,439 and another form in the Leonhardt patent, U.S. Pat. No. 3,787,992. In two part hinged boxes, it has been the pratice to cover the inside of the boxes with a covering that extended from one box to the other and two individual mats. It is desirable in a picture frame assembly to have a unit which may be quickly assembled by the user which is pleasing in appearance and which utilizes a minimum number of parts. This is achieved in a folding picture frame assembly that may contain two photographs by utilizing a simple two part folding box and a unitary mat.